The present invention relates to a method for generating a flexible display field for a video surveillance system.
Video surveillance systems are used for instance for central monitoring in department stores, parking garages, museums, banks, and so forth, using a plurality of video cameras distributed at various positions. To that end, the image data streams of the individual video cameras are combined and shown either on a plurality of monitors or on a single monitor that has a plurality of image windows.
Displaying a plurality of image fields on a screen is known for instance from German Patent Disclosure DE 197 54 983, which discloses a method for transmitting and/or displaying information. In this method, an intermediate film that interrupts a main film upon transmission and/or display in one field has a display of scenes from the main film superimposed on it, to keep viewers from switching over to a different program even during the intermediate film.
U.S. Pat. No. 6,476,858 B1 involves a video surveillance and security system. In this system, a plurality of information windows are incorporated into a main window, and in each of them a sequence of images, for instance from a surveillance camera, is shown. The size and location of the information windows are set either automatically by the operating system on which the system is based and/or manually by the user. The information windows are continuously adjustable.
In modern digital video surveillance systems, it is by now usual for live video images and optionally other information, such as site plans, to be shown simultaneously in a plurality of information windows, also called “cameos”, by means of the processing software. Current software products use two alternative types of display as a user interface: One alternative provides that the individual information windows are not coherent and thus can be individual shifted, reduced and increased in size, or overlapped. In the other alternative, the images shown share a common display field, and the information windows are arranged in regular grids, such as 2×2, 3×3, 4×4, or in irregular grids, such as 5.1, 7.1. This last alternative for the type of display forms the closest prior art.